The present invention relates to a quick disconnect coupling device suitable for connecting an externally splined power take-off shaft to a corresponding internally splined yoke with a universal joint and particularly to a coupling device which incorporates a twist collar having an internal torsion spring rotatable through a predetermined angle for automatically locking the device axially onto the shaft by way of one locking ball.
The problem of coupling one shaft to another for transmitting a torque force is a problem that has long existed in the agricultural industry. Agricultural tractors are normally equipped with a splined power take-off shaft to which the shaft of a towed or mounted agricultural implement is connected by means of a coupling mechanism which conventionally includes an internally splined member mating with the splined power take-off shaft and having a universal joint. Such mechanisms also generally include a releasable lock for preventing the inadvertent axial separation of the mating splined members. One example of such torque transmitting coupling is disclosed in U.S. Pat. No. 4,859,110--Dommel.
The present coupling device provides a simplified inexpensive mechanism utilizing a single acting cam surface engageable by a single locking ball that insures a tight lock-up on the power take-off shaft as the mating splined parts wear. The present coupling device in addition to housing the single acting cam surface includes a torsional spring constructed so as to use the interior cylindrical surface of the twist collar and the outside cylindrical surface of the internally splined member as stops which define the predetermined angle through which the spring may be rotated.